OG 28问个低级问题,介词是否不能跟从句?

看了OG很多说介词不能接从句,但有时候觉得它也跟从句啊,现在一时找不到例子,但

I am very disappointed at what he said.

这个what he said不是at介词后的从句么?

找到OG 11 28题

28．  In reference to the current hostility toward smoking．smokers frequently expressed anxiety that their prospects for being hired and promoted are being stunted by their habit．

(A)  In reference to the current hostility toward smoking，smokers frequently expressed anxiety that

(B)  Referring to the current hostility toward smoking，smokers frequently expressed anxiety about

(C)  When referring to the current hostility toward smoking，smokers frequently express anxiety about

(D)  With reference to the current hostility toward smoking，smokers frequently expressed anxiety about

(E)  Referring to the current hostility toward smoking，smokers frequently express anxiety that

about后不能跟从句, 要用that, 那么是否跟我上面那个例子矛盾啊?还是我自己将自己弄晕了?谢谢啊.

I am very disappointed at what he said.

what可以看作是the thing that

Your sentence can be transfer to "I am very disappointed at the thing that he said". What followed by "at" is "the thing", not the subordinate clause.